The superior waryngeaw nerve consists of two branches: de internaw waryngeaw nerve (sensory), which suppwies sensory fibers to de waryngeaw mucosa, and de externaw waryngeaw nerve (motor), which innervates de cricodyroid muscwe.

The recurrent waryngeaw nerve gets its name from de fact dat it woops bewow de aorta on its way to de intrinsic muscwes of de warynx. The weft recurrent waryngeaw nerve passes under and around de aorta on its way to de warynx, whereas de right recurrent waryngeaw nerve passes under and around de subcwavian artery. Because de aorta is inferior to de subcwavian artery, de weft recurrent waryngeaw nerve is a bit wonger dan de right recurrent waryngeaw nerve. However, dere is no discernibwe effect on de timing of neuraw impuwses to de muscwes dese two nerves serve. By comparison wif de recurrent waryngeaw nerves, de superior waryngeaw nerve takes a more direct route on de way to de cricodyroid muscwes.[1]

The internaw waryngeaw nerve is de internaw branch. It descends to de dyrohyoid membrane, piercing it in company wif de superior waryngeaw artery, and is distributed to de mucous membrane of de warynx. Of dese sensory branches, some are distributed to de epigwottis, de base of de tongue, and de epigwottic gwands; oders pass posteriorwy, in de aryepigwottic fowd, to suppwy de mucous membrane surrounding de entrance of de warynx, and de mucous wining of de warynx as far down as de vocaw fowds.

A fiwament descends beneaf de mucous membrane on de inner surface of de dyroid cartiwage and joins de recurrent nerve. Above de vocaw fowds de sensory innervation of de warynx is via de internaw waryngeaw nerve. Bewow de vocaw fowds it is by way of branches of de recurrent waryngeaw nerve. The vocaw fowd itsewf receives duaw innervation from bof nerves.

A superior waryngeaw nerve pawsy changes de pitch of de voice and causes an inabiwity to make expwosive sounds due to parawysis of de cricodyroid muscwe. If no recovery is evident dree monds after de pawsy initiawwy presents, de damage is most wikewy to be permanent. A biwateraw pawsy presents as a tiring and hoarse voice. Damage to de superior waryngeaw nerve weaves de vocaw cord abducted and poses an aspiration risk. It can be injured in surgery invowving de removaw of de dyroid gwand (dyroidectomy).[2][3]
Understanding de most common anatomic variations of de distaw portion of de externaw waryngeaw nerve and its rewation to de inferior constrictor muscwe is criticaw and awwows identifying and preserving de integrity of dis nerve in most cases.[4][5]
The externaw branch is susceptibwe to damage during dyroidectomy or cricodyrotomy, as it wies immediatewy deep to de superior dyroid artery. The abiwity to produce pitched sounds is den impaired awong wif easy voice fatigabiwity, (usuawwy mono-toned voice).

Irritation of de internaw waryngeaw nerve resuwts in uncontrowwed coughing - usuawwy as a resuwt of food or water in de waryngopharynx.
The wesion of dis branch (for exampwe, during surgery dat seeks an anterior approach to de cervix, is associated wif a woss of de waryngeaw refwex of cough and an ewevate risk of aspiration pneumonia.[6]